TENTH REPORT OF THE STATE ENTOMOLOGIST 



393 



If the winter is comparatively mild, they may be seen for the first in 

 the latter part of February, but ordinarily they do not attract attention 

 until in March. They are in great abundance in the last weeks of 

 March and through April and become comparatively few in May, per- 

 haps by deserting the cellars for outdoor life. He had never had rea- 

 son to regard them as harmful to mushrooms. At the time of writing 

 (March 25, 1889) there were thousands of the flies in the mushroom 

 cellars, while at the same time the crop of mushrooms was the finest 

 and cleanest that he had ever grown and showing no sign of attack by 

 larvfe of any kind. They are certainly no hindrance to mushroom 

 growing during the winter, for they never appear in the earlier months 

 or until the manure is at least two months old; but they are disagree- 

 able guests, for \ efore the end of April the walls appear as if they 

 had been washed with wtt mud, so much dirt and moisture do they 

 gather and leave upon the wallja, on «hich they are constantly leaping 

 from the beds and coursing over. Mr. Falconer did not think it possi- 

 ble that these flies can be identical with those that produce the " mag- 

 gots " that infest mushrooms in the month of April. In this opinion 

 he was correct, as will appear in subsequent pages. 



Remedies Suggested. 



If it should be found on closer observation that it is important that 

 the larvfe of these flies should be destroyed, there should be no diffi- 

 culty in killing them by occasional applications of pure and fresh pyre- 

 thrum in water, using it of the strength of one ounce to from four to 

 eight gallons of water, as the larvae may be deeper beneath or nearer 

 to the surface of the beds. That they multiply with great rapidity is 

 shown by the fact that the fifth diy after some surface-feeding larvae 

 were seen to enter the ground the winged flies therefrom made their 

 appearance. 



A method for killing the flies, said by Mr. Falconer to be employed 

 in mushroom cellars in France, might also be used in connection with 

 pyrethrum solution. It is to place small lighted lamps in shallow pans 

 filled with water, with a little kerosene floated on the surface. Vast 

 numbers are attracted to the lights and killed by falling into the kero- 

 sene, but still it does not prove wholly effectiv.e, as there are always 

 many left. 



The Manure-Fly Undescribed. 



Of the twenty-three United States Sciaras of the Osten Sacken Cata- 

 logue, the " manure-fly " (adopting Mr. Falconer's name for it) can not 

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